Difference between revisions of "cpp/utility/functional/less"
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===Notes=== | ===Notes=== | ||
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===Member types=== | ===Member types=== | ||
Revision as of 13:07, 14 October 2012
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<td>Defined in header
</td>
<functional>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td class="t-dcl-nopad">template< class T >
struct less;
</td>
struct less;
<td class="t-dcl-nopad"> </td> <td class="t-dcl-nopad"> </td> </tr> Template:ddcl list end
Function object for performing comparisons. Uses operator< on type T.
Contents |
Notes
Implementation-defined strict total order over pointers
A specialization of std::less for any pointer type yields the implementation-defined strict total order, even if the built-in operator< operator does not.
The implementation-defined strict total order is consistent with the partial order imposed by built-in comparison operators (<=>,(since C++20)<, >, <=, and >=), and consistent among following standard function objects:
- std::less, std::greater, std::less_equal, and std::greater_equal, when the template argument is a pointer type or void(since C++14)
| (since C++20) |
Member types
| type | definition |
result_type
|
bool
|
first_argument_type
|
T
|
second_argument_type
|
T
|
Member functions
| operator() |
checks if the first argument is less than the second (public member function) |
std::less::operator()
| bool operator()( const T& lhs, const T& rhs ) const; |
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Checks whether lhs is less than rhs.
Parameters
| lhs, rhs | - | values to compare |
Return value
true if lhs < rhs, false otherwise.
Exceptions
(none)
Possible implementation
bool operator()(const T &lhs, const T &rhs) const { return lhs < rhs; } |
